bionic (3) dom.3tcl.gz

Provided by: tdom_0.9.0-1_amd64 bug

NAME

       dom - Create an in-memory DOM tree from XML

SYNOPSIS

       package require tdom

       dom method ?arg arg ...?
_________________________________________________________________

DESCRIPTION

       This  command  provides  the creation of DOM trees in memory. In the usual case a string containing a XML
       information is parsed and converted into a DOM tree. Other possible parse input may be HTML or JSON.  The
       method indicates a specific subcommand.

       The valid methods are:

       dom parse ?options? ?data?
              Parses  the XML information and builds up the DOM tree in memory providing a Tcl object command to
              this DOM document object. Example:

                     dom parse $xml doc
                     $doc documentElement root

              parses the XML in the variable xml, creates the DOM tree  in  memory,  make  a  reference  to  the
              document  object, visible in Tcl as a document object command, and assigns this new object name to
              the variable doc. When doc gets freed,  the  DOM  tree  and  the  associated  Tcl  command  object
              (document and all node objects) are freed automatically.

                     set document [dom parse $xml]
                     set root     [$document documentElement]

              parses  the  XML  in  the  variable  xml,  creates the DOM tree in memory, make a reference to the
              document object, visible in Tcl as a document object command, and returns this  new  object  name,
              which  is then stored in document.  To free the underlying DOM tree and the associative Tcl object
              commands (document + nodes + fragment nodes) the document object  command  has  to  be  explicitly
              deleted by:

                     $document delete

              or

                     rename $document ""

              The valid options are:

              -simple
                     If  -simple  is  specified,  a  simple  but  fast parser is used (conforms not fully to XML
                     recommendation). That should double parsing and DOM generation speed. The encoding  of  the
                     data  is not transformed inside the parser. The simple parser does not respect any encoding
                     information in the XML declaration. It skips over the internal DTD subset and  ignores  any
                     information  in  it. Therefore it doesn't include defaulted attribute values into the tree,
                     even if the according attribute declaration is in the  internal  subset.  It  also  doesn't
                     expand  internal  or  external  entity  references  other  than the predefined entities and
                     character references.

              -html  If -html is specified, a fast HTML parser is used, which tries to even parse  badly  formed
                     HTML into a DOM tree.

              -html5 This  option  is  only available if tDOM was build with --enable-html5. Try the featureinfo
                     method if you need to know if this feature is build in. If -html5 is specified,  the  gumbo
                     lib  html5  parser  (https://github.com/google/gumbo-parser) is used to build the DOM tree.
                     This is, as far as it goes, XML namespace-aware. Since this probably isn't wanted by a  lot
                     of users and adds only burden for no good in a lot of use cases -html5 can be combined with
                     -ignorexmlns, in which case all nodes and attributes in the DOM tree  are  not  in  an  XML
                     namespace. All tag and attribute names in the DOM tree will be lower case, even for foreign
                     elements not in the xhtml, svg or mathml namespace. The DOM tree may  include  nodes,  that
                     the parser inserted because they are implied by the context (as <head>, <tbody>, etc.).

              -json  If  -json  is  specified,  the data is expected to be a valid JSON string (according to RFC
                     7159). The command returns an ordinary DOM document with nesting token inside the JSON data
                     translated  into  tree  hierarchy.  If a JSON array value is itself an object or array then
                     container element nodes named (in  a  default  build)  arraycontainer  or  objectcontainer,
                     respectively, are inserted into the tree. The JSON serialization of this document (with the
                     domDoc method asJSON) is the same JSON information as the data, preserving JSON  datatypes,
                     allowing non-unique member names of objects while preserving their order and the full range
                     of JSON string  values.  JSON  datatype  handling  is  done  with  an  additional  property
                     "sticking" at the doc and tree nodes. This property isn't contained in an XML serialization
                     of the document. If you need to store the JSON data represented by a  document,  store  the
                     JSON  serialization and parse it back from there. Apart from this JSON type information the
                     returned doc command or handle is an  ordinary  DOM  doc,  which  may  be  investigated  or
                     modified with the full range of the doc and node methods. Please note that the element node
                     names and the text node values within the tree may be outside of what the  appropriate  XML
                     productions allow.

              -jsonmaxnesting  integer
                     This  options  only  has  effect  if  used  together  with  the  -json  option. The current
                     implementation uses recursive descent JSON parser. In order to  avoid  using  excess  stack
                     space, any JSON input that has more than a certain levels of nesting is considered invalid.
                     The default maximum nesting is 2000. The option -jsonmaxnesting allows the user  to  adjust
                     that.

              --     The  option  --  marks  the end of options.  While respected in general this option is only
                     needed in case of parsing JSON data, which may start with a "-".

              -keepEmpties
                     If -keepEmpties is specified then text nodes which contain only whitespaces will be part of
                     the resulting DOM tree. In default case (-keepEmpties not given) those empty text nodes are
                     removed at parsing time.

              -channel  <channel-ID>
                     If -channel <channel-ID> is specified, the input to be parsed is read  from  the  specified
                     channel.  The  encoding  setting of the channel (via fconfigure -encoding) is respected, ie
                     the data read from the channel are converted to UTF-8 according to  the  encoding  settings
                     before the data is parsed.

              -baseurl  <baseURI>
                     If  -baseurl  <baseURI>  is specified, the baseURI is used as the base URI of the document.
                     External entities references in the document are resolved relative to this base  URI.  This
                     base URI is also stored within the DOM tree.

              -feedbackAfter  <#bytes>
                     If -feedbackAfter <#bytes> is specified, the tcl command given by -feedbackcmd is evaluated
                     at the first element start within the document (or an external entity) after the  start  of
                     the  document  or  external  entity  or  the  last  such  call  after  #bytes. For backward
                     compatibility  if  no  -feedbackcmd  is   given   but   there   is   a   tcl   proc   named
                     ::dom::domParseFeedback  this  proc is used as -feedbackcmd. If there isn't such a proc and
                     -feedbackAfter is used it is an error to not also use -feedbackcmd. If  the  called  script
                     raises  error,  then  parsing  will  be aborted, the dom parse call returns error, with the
                     script error msg as error msg.  If the called script return -code break, the  parsing  will
                     abort and the dom parse call will return the empty string.

              -feedbackcmd  <script>
                     If  -feedbackcmd <script> is specified, the script script is evaluated at the first element
                     start within the document (or an external entity)  after  the  start  of  the  document  or
                     external  entity  or  the  last  such  call  after #bytes value given by the -feedbackAfter
                     option. If -feedbackAfter isn't given, using this option doesn't has  any  effect.  If  the
                     called script raises error, then parsing will be aborted, the dom parse call returns error,
                     with the script error msg as error msg. If  the  called  script  return  -code  break,  the
                     parsing will abort and the dom parse call will return the empty string.

              -externalentitycommand  <script>
                     If  -externalentitycommand  <script>  is  specified,  the specified tcl script is called to
                     resolve any external entities of the document. The actual  evaluated  command  consists  of
                     this  option followed by three arguments: the base uri, the system identifier of the entity
                     and the public identifier of the entity. The base uri and the public identifier may be  the
                     empty  list.  The  script  has to return a tcl list consisting of three elements. The first
                     element of this list signals  how  the  external  entity  is  returned  to  the  processor.
                     Currently  the two allowed types are "string" and "channel". The second element of the list
                     has to be the (absolute) base URI of the external entity to be parsed.  The  third  element
                     of  the list are data, either the already read data out of the external entity as string in
                     the case of type "string", or the name of a tcl channel, in the  case  of  type  "channel".
                     Note  that if the script returns a tcl channel, it will not be closed by the processor.  It
                     must be closed separately if it is no longer needed.

              -useForeignDTD  <boolean>
                     If <boolean> is true and the document does not have an external  subset,  the  parser  will
                     call  the  -externalentitycommand  script  with  empty values for the systemId and publicID
                     arguments. Please note that if the document also  doesn't  have  an  internal  subset,  the
                     -startdoctypedeclcommand  and  -enddoctypedeclcommand  scripts, if set, are not called. The
                     -useForeignDTD respects

              -paramentityparsing  <always|never|notstandalone>
                     The -paramentityparsing option controls, if  the  parser  tries  to  resolve  the  external
                     entities  (including  the external DTD subset) of the document while building the DOM tree.
                     -paramentityparsing requires an argument,  which  must  be  either  "always",  "never",  or
                     "notstandalone".   The value "always" means that the parser tries to resolves (recursively)
                     all external entities of the XML source. This is the default in case -paramentityparsing is
                     omitted.  The  value "never" means that only the given XML source is parsed and no external
                     entity  (including  the  external  subset)  will  be  resolved  and   parsed.   The   value
                     "notstandalone"  means,  that  all  external entities will be resolved and parsed, with the
                     execption of documents, which explicitly states standalone="yes" in their XML declaration.

              -ignorexmlns
                     It is recommended, that you only use this option with the -html5 option. If this option  is
                     given,  no node within the created DOM tree will be internally marked as placed into an XML
                     Namespace, even if there is a default namespace in scope for un-prefixed elements  or  even
                     if  the  element  has  a  defined  namespace  prefix.  One  consequence  is that XPath node
                     expressions on such a DOM tree doesn't work as expected. Prefixed element  nodes  can't  be
                     selected  and element nodes without prefix will be seen by XPath expressions as if they are
                     not in any namespace (no matter if they are in fact should be in a default namespace).

       dom createDocument docElemName ?objVar?
              Creates a new DOM document object with one element node with node  name  docElemName.  The  objVar
              controls the memory handling as explained above.

       dom createDocumentNS uri docElemName ?objVar?
              Creates  a new DOM document object with one element node with node name docElemName. Uri gives the
              namespace of the document element to create. The objVar controls the memory handling as  explained
              above.

       dom createDocumentNode ?objVar?
              Creates  a  new  'empty'  DOM document object without any element node. objVar controls the memory
              handling as explained above.

       dom setResultEncoding ?encodingName?
              This option is for backward compatibility with Tcl 8.0. If  tDOM  is  build  with  any  newer  Tcl
              version  this  option  does  not  has  any effect. If encodingName is not given the current global
              result encoding is returned. Otherwise the global result encoding is  set  to  encodingName.   All
              character  data,  attribute values etc. will then be converted from UTF-8, which is delivered from
              the Expat XML parser, to the given 8 bit  encoding  at  XML/DOM  parse  time.   Valid  values  for
              encodingName  are:  utf-8,  ascii,  cp1250, cp1251, cp1252, cp1253, cp1254, cp1255, cp1256, cp437,
              cp850, en, iso8859-1, iso8859-2, iso8859-3, iso8859-4, iso8859-5, iso8859-6, iso8859-7, iso8859-8,
              iso8859-9, koi8-r.

       dom    createNodeCmd   ?-returnNodeCmd?   ?-tagName   name?   ?-jsonType   jsonType?   ?-namespace   URI?
       (element|comment|text|cdata|pi)Node commandName
              This method creates Tcl commands, which in turn create tDOM nodes. Tcl commands  created  by  this
              command  are  only  avaliable  inside  a  script  given to the domNode methods appendFromScript or
              insertBeforeFromScript. If a command created with createNodeCmd is invoked in any  other  context,
              it  will  return error. The created command commandName replaces any existing command or procedure
              with that name. If the commandName includes  any  namespace  qualifiers,  it  is  created  in  the
              specified  namespace.  The -tagName option is only allowed for the elementNode type. The -jsonType
              option is only allowed for elementNode and textNode types.

              If  such  command  is  invoked  inside  a  script  given  as  argument  to  the   domNode   method
              appendFromScript  or insertBeforeFromScript it creates a new node and appends this node at the end
              of the child list of the invoking element node.  If  the  option  -returnNodeCmd  was  given,  the
              command  returns  the created node as Tcl command. If this option was omitted, the command returns
              nothing. Each command creates always the same type of node.  Which type of node is created by  the
              command  is  determined  by  the  first  argument  to the createNodeCmd. The syntax of the created
              command depends on the type of the node it creates.

              If the command type to create is elementNode, the created command will create an element node,  if
              called.  Without  the  -tagName  option  the  tag  name of the created node is commandName without
              namespace qualifiers. If the -tagName option was  given  then  the  created  command  the  created
              elements will have this tag name. If the -jsonType option was given then the created node elements
              will have the given JSON type. If the -namespace option is given the created element node will  be
              XML namespaced and in the namespace given by the option. The element name will be literal as given
              either by the command name or the -tagname option, if that was given. An appropriate XML namespace
              declaration  will  be automatically added, to bind the prefix (if the element name has one) or the
              default namespace (if the element name hasn't a prefix) to the namespace if such a  binding  isn't
              in scope.

              The syntax of the created command is:

                     elementNodeCmd ?attributeName attributeValue ...? ?script?
                     elementNodeCmd ?-attributeName attributeValue ...? ?script?
                     elementNodeCmd name_value_list script

              The command syntax allows three different ways to specify the attributes of the resulting element.
              These could be specified with attributeName attributeValue argument pairs, in  an  "option  style"
              way with -attriubteName attributeValue argument pairs (the '-' character is only syntactical sugar
              and will be stripped off) or as a Tcl list with elements interpreted as  attribute  name  and  the
              corresponding  attribute  value.   The  attribute name elements in the list may have a leading '-'
              character, which will be stripped off.

              Every elementNodeCmd accepts an optional Tcl script as last argument. This script is evaluated  as
              recursive  appendFromScript  script  with  the node created by the elementNodeCmd as parent of all
              nodes created by the script.

              If the first argument of the method is textNode, the command will  create  a  text  node.  If  the
              -jsonType  option was given then the created text node will have that JSON type. The syntax of the
              created command is:

                     textNodeCmd ?-disableOutputEscaping? data

              If the optional flag -disableOutputEscaping is given, the escaping of the ampersand character  (&)
              and the left angle bracket (<) inside the data is disabled. You should use this flag carefully.

              If the first argument of the method is commentNode or cdataNode the command will create an comment
              node or CDATA section node. The syntax of the created command is:

                     nodeCmd data

              If the first argument of the method is piNode, the command will create  a  processing  instruction
              node. The syntax of the created command is:

                     piNodeCmd target data

       dom setStoreLineColumn ?boolean?
              If  switched  on, the DOM nodes will contain line and column position information for the original
              XML document after parsing. The default is not to store line and column position information.

       dom setNameCheck ?boolean?
              If NameCheck is true, every method which  expects  an  XML  Name,  a  full  qualified  name  or  a
              processing instructing target will check, if the given string is valid according to its production
              rule. For  commands  created  with  the  createNodeCmd  method  to  be  used  in  the  context  of
              appendFromScript the status of the flag at creation time decides. If NameCheck is true at creation
              time, the command will check its arguments, otherwise not. The  setNameCheck  set  this  flag.  It
              returns the current NameCheck flag state. The default state for NameCheck is true.

       dom setTextCheck ?boolean?
              If TextCheck is true, every command which expects XML Chars, a comment, a CDATA section value or a
              processing instructing value will check, if the given string is valid according to its  production
              rule.  For  commands  created  with  the  createNodeCmd  method  to  be  used  in  the  context of
              appendFromScript the status of the flag at creation time decides. If TextCheck is true at creation
              time,  the command will check its arguments, otherwise not.The setTextCheck method sets this flag.
              It returns the current TextCheck flag state. The default state for TextCheck is true.

       dom setObjectCommands ?(automatic|token|command)?
              Controls if documents and nodes are created as tcl commands or  as  token  to  be  used  with  the
              domNode  and  domDoc  commands. If the mode is 'automatic', then methods used at tcl commands will
              create tcl commands and methods used at doc or node tokes will  create  tokens.  If  the  mode  is
              'command' then always tcl commands will be created. If the mode is 'token', then always token will
              be created. The method returns the current mode. This method is an experimental interface.

       dom isName name
              Returns 1 if name is a valid XML Name according to production 5 of  the  XML  1.0  recommendation.
              This means that name is a valid XML element or attribute name. Otherwise it returns 0.

       dom isPIName name
              Returns  1  if name is a valid XML processing instruction target according to production 17 of the
              XML 1.0 recommendation. Otherwise it returns 0.

       dom isNCName name
              Returns 1 if name is a valid NCName according to production 4 of the  of  the  Namespaces  in  XML
              recommendation. Otherwise it returns 0.

       dom isQName name
              Returns  1  if  name  is  a  valid QName according to production 6 of the of the Namespaces in XML
              recommendation. Otherwise it returns 0.

       dom isCharData string
              Returns 1 if every character in string is a valid XML Char according to production 2  of  the  XML
              1.0 recommendation. Otherwise it returns 0.

       dom isBMPCharData string
              Returns  1  if  every character in string is a valid XML Char with a Unicode code point within the
              Basic Multilingual Plane (that means, that every character within the string is at  most  3  bytes
              long). Otherwise it returns 0.

       dom isComment string
              Returns  1  if string is a valid comment according to production 15 of the XML 1.0 recommendation.
              Otherwise it returns 0.

       dom isCDATA string
              Returns 1 if string is valid according to production 20 of the XML 1.0  recommendation.  Otherwise
              it returns 0.

       dom isPIValue string
              Returns  1  if string is valid according to production 16 of the XML 1.0 recommendation. Otherwise
              it returns 0.

       dom featureinfo feature
              This method provides information about the used build options and the  expat  version.  The  valid
              values for the feature argument are:

              expatversion
                     Returns   the   version  of  the  underlyling  expat  version  as  string,  something  like
                     "exapt_2.1.0". This is what the expat API function XML_ExpatVersion() returns.

              expatmajorversion
                     Returns the major version of the underlyling expat version as integer.

              expatminorversion
                     Returns the minor version of the underlyling expat version as integer.

              expatmicroversion
                     Returns the micro version of the underlyling expat version as integer.

              dtd    Returns as boolean if build with --enable-dtd.

              ns     Returns as boolean if build with --enable-ns.

              unknown
                     Returns as boolean if build with --enable-unknown.

              tdomalloc
                     Returns as boolean if build with --enable-tdomalloc.

              lessns Returns as boolean if build with --enable-lessns.

              TCL_UTF_MAX
                     Returns the TCL_UTF_MAX value of the tcl core, tDOM was build with as integer

              html5  Returns as boolean, if build with --enable-html5.

KEYWORDS

       XML, DOM, document, node, parsing